Automatic cradle type stoker



L L E A. H.

AUTOMATIC CRADLE TYPE STOKER 5 Sheets-Sheet l Filed May l0, 1946 wv% mm mw March 7, 1950 H. A. ELLIS AUTOMATIC CRADLE TYPE sToKER ssheets-sheet 2 Filed May 1o. 194e March 7, 1950 H. A. ELLIS AUTOMATIC CRADLE TYPE `STOKER Filed May 1o, 194.6

5 Sheets-Sheet 3 IWW l 75 Syvum/wom,

HuMPH/esy A. ELL/5,

March 7 1950 H. AQELLIS AUTOMATIC CRADLE TYPE sToKER 5 Sheets-Sheet 4 Filed May l0. 1946 March 7, 1950 H. A, ELLIS 294997735 AUTOMATIC CRADLE TYPE sToKER Filed May l0, 1946 5 Sheets-Sheet 5 Patented Mar. 7, 1950 UNITED STATES PATENT OFFICE AUTOMATIC CRADLE TYPE STOKER Humphrey A, Ellis, Fort Wayne, Ind. y Application May 10, 1946, Serial No. 668,917

I (c1. 11o- 39) 11 Claims. 1 i

This invention relates to an automatic cradle type stoker and it aims generally to provide a more efficient, practical and durable' construc-A tion which will burn all grades of `coal in minimum time, without manual intervention, and at reduced cost in manufacture, installation and operation.

A further desideratum is to provide an organization of parts which will maintain the fuel bed of uniform thickness and density, will have a novel motion to agitate the fuel bed to break up coking formations and to discharge ashes and which, more in detail, while fuel is being fed forward by ram means, will move the entire fuel mass in the opposite direction or toward the supply of fuel to meet or abut it to break up or crush the fuel bed. I prevent formation of a dense coking mat and maintain uniform porosity.

Further objects are to provide a construction having a plurality of movable grate sections, certain of which contain air distributing compartments beneath grates proper associated with forced air feeding means; such a construction wherein the forced air feeding means has duct means with connections between same and the associated sections engaging on curved wiping surfaces: a construction in which one of the sections at its ton forms a hearth and coa-cts with a removable fuel feed plate means resting at one end thereon and intertted with the furnace wall; a construction wherein the grate sections are unitarily movable and have bearing engagement with sealingr bars pivotally connected by links; a con' struction wherein the grate sections are inclined forwardly and are unitarily movable in a direc#l tion in opposition to motion 'of ajram means ."to

facilitate breaking up the caking or coking'o'f bituminous coal to obtain better combustion: within the fuel bed; a construction affording a-v novel mounting and drive for the ram means; a construction wherein all grate sections inthe main are capable of manufacture by use of' the same pattern; and a construction having novel.: valves. gates orequivalent means to control the admission of forced air into each' of the a'forc-T said distributing compartments.

The present application is a continuation in part cf'my abandoned application Serial Number 344,824, iiled July 10, 1940, and my abandoned application Serial Number 454,585, led August 412, i942, .each for an automatic cradle type stoke'r.'v 1 Various objects land advantages additionalto" those mentioned will in part be pointed out andy scription followingl taken in connection-withltle 55 become evident from a considerationof the de# accompanying drawings illustrating an operative embodiment.

In said drawings:

Figure 1 is a view primarily showing the Stoker or grate in central longitudinal section and in connection with a feed hopper and brick setting, theA latter being shown in longitudinal section and partly broken away;

Figurez is a view of the parts of Figure 1 showing the setting in horizontal section and the other parts in plan;

Figure 3 is a front elevation;

Figurei is a detail vertical section taken on the plane of line 4 4 of Figure 2;

Figure 5 is an enlarged longitudinal sectional detail of the ram actuating eccentric means;

Figure 6 is a diagram of the grate surfaces when at their front limit of movement;

Figure '7 is a diagram of the upper or grate surfaces of the grate sections when at their rearwardA limit of movement;

Figure 8 is a perspective View of one of the sealing bars for the grate sections;

Figure 9 is a perspective view showing thev air duct connection between the main air `duct and grate sections, the sections of the connection being separated to disclose their details;

Figure 10 is a fragmentary view in perspective showing the shaker bar connection to the stud bracket of one of the stoker sections;

Figure' 11 is a perspective view of one of the air dei'lectors employed in the stoker sections;-

Figures 12 and 13, respectively, are end and side views of one ofthe links used in articulately connectingthe stoker sections tothe bearing and sealing bars.

Referring specifically to the drawings, whereinf like reference characters designate like or smi' lar parts throughout the different views, the structure is installed or builtv into a brick, usually metabreinforced, or other suitable setting as at l0 having a usual discharge chimney (not shown) A metallic front wall `is provided at l I' onto which a coal hopper I2'is built or attached. At the: bottom of the hoppen-I provide one or more feed openings' y I3 through which the coal falls by gravity forfeed into the stoker by reciprocatory or oscillatory motion of one or more rams I4.

The fuel which passes through the openings I3 forms abcd of approximately uniform depth on siredjnumbi' of the latter being employed.

ta'lliciboxes or" compartments Il provided with suitable grates across the top. The grate of section I5 is designated I5I and the grates of the sections I6 are designated IGI. While the grates |5| and ISI specifically form no part of the invention, they may be built up in any suitable way and it is to be understood that they may be arranged most advantageously and usually above the boxes to minimize burring of the grates, and also that the grate bars may optionally be arranged at a right-angle to the l position now shown. All of said grates are made up ofspaced bars |63, such -bars in the case of grates |5I and, IBI being in staggered rows as shown so that tortuous passages are formed betweenthem and; 'i if one row burns away the row beneath will continue to function.

The boxes 0r compartments I'I have suitable. air deflectors I'Il therein adjacent openings IBin their bottom walls and attached to the boxes around such `openings as by welding or bolting, aregenerally rectangular coupling or conduit sec; tions I9 resting on or disposed in wiping contact at lower spherical surfaceszz with theupperspherical surfaces 2| of coupling or conduit sections 22as shown. Such sections I9 and 22 are detailed in Figure 9 and sections 22 are suitably mounted on a sectional air supply duct or conduit I8 as by welding or bolting thern in place around outlet openings 23 therein. The openingsior passages ISI and 2II through the coupling sections may be round or of any preferred shape.

Wall II may have inspection openings III therethrough normally covered by pivoted closuresfI I2.

Loose bearing and sealing bars 24 (Figs. l, and') are 'located and balanced at the tops of the lboxes I'I, one on each side thereof, between the sides of the boxes and bars or beams 21 mounted on the side walls of the setting III. Bars 24 are of approximatelythe'same extent lengthwise of the stoker as the boxes I1 and they have rectilinear flanges or walls 25 slidably engagedwith overhanging flanges 25 of said beams 21. Aligned studs or pins 28 are provided on opposlte sides of each box I'Iand they are engaged in downwardly open arcuate bearings v29 integral withbars'at vertical fianges `25| thereof. Sufflcient clearance is provided between sections l5 and I6 at the top and between the studs 28 and bars 24 and associated parts to enable sliding of the bars 24 along anges 25 incidental to oscilla tion crrocking of the sectionsl I6 and I1 `from the normal position of Figure 1 to a rearward limit and forward limit as diagrammaticallysuggested in Figures 6 and '7, respectively. Bars 2,4 although slidable, at all times remain practically `parallel toand in substantial contact with flanges 26'to prevent leakage or loss of fuel by Vfalling from the sides of the grates, especially in the spaces which otherwise would result when 'the gratesor boxes are rocked or tilted.

The aforesaid sections I5 and 'IBare adapted to be `simultaneously reciprocated oroscillated on the axesfrorn which the arcs' of 'surfaces 2U and 2| are struck andto this end the bars 24 are in articulate linkage .by reason of the loose pivotal connection of links 30 at k3i to lugs 32 on adjacent bars. Links 30 may be in sections connected by bolts 33 with one or more shirns 33| interposed for adjustment as ,to length. One or more links or pitmen V34 are .pivoted to adjacent boxes -i'l 'as at `35 to lugs '342 of the brackets thereof carrying studs28, and pass tothe exterior through `openings in :the frontwalli I.; .;1?tmen 34 are preferably two in number and arranged on opposite sides of the boxes I'I and each has a yoke or strap 39 in which a crank or eccentric 4I) is disposed. A horizontal rock shaft 42 on which 5 said cranks 40 are fastened, is disposed across the exterior of wall I| journaled at intervals in suitable bearings 42 carried by brackets 36 fastened to the wall. Said shaft 4I is coupled at 43 to the shaft 44 of a conventional reduction gearing unit 45 suitably supported at the front of the apparatus. n'The shaft 4I may be mounted in any suitable manner and driven through the reduction unit 45 f ,byianypvrefffnredmeans. As shown, it is driven i from an electric motor 49, mounted adjacent unit 45, by abelt'drive 5 I. The motion nf shaft 4| is utilized to reciprocate the rains I4 in a direction opposite to the direction of reciprocation of the stoker sections I5 and IE. Said shaft 4I has crank disks or eccentrios :53; thereon surrounded by straps I540i links 5.5 which-in turnarepivoted at 5S to and between'pairs'V of levers -5'I pivotally'eonnected .at their lowerends at-58 to brackets 59 convenientlyfastenedto'the outer wall ofvhopperIZ. Short links Yor connecting rods Gil arepivoted tc the levers 51 at 6| and pivoted at 62 to the rams I4. A'lt-will-lce notedv that the front half of the upper surface of `section i5 is an imperforate plate or :hearth having a convexupper surfacathe arc of which is struck from the pivotal axis of such section. This section IE'is entirely within the furnace and is Aof suchshape and size that the same patterns as are used in castingthe parts of sections I6, for the most part, may be Vused in casting the parts' thereof.

Therams VHI slide in slightlyinolined .Chutes 56 which Vmay be eitherseparate or integral with the hopper I2 and wall II, with which'chutes theropenings I8 communicate and which lead to theinteriorofthe furnace. The bottoni wallsof chutesSS-.may be Vof hardermetal than theremaindertobetter withstandwear. One or `more removable hearth plates 51 extend from .wall I `I and. their uppersurf aces are ush with the upper surfaces ofthe bottom Walls yof chutes .65. Said hearthtplates 6I having depending ribs or flanges 68 seated in grooves `6,9 formed by offset brackets 1I lon Ywall At the inner edges. hearthplates ETI overlap and rest on the plate .65. Said `'hearth plates 67 may be readily removed laterally to Vfacilitate replacement, cleaning, inspection orrepair'of adjacent'parts. At each side of fthe passages i3, diverging fioor walls .'I are ,provided within the hopper" I 2.

- The 4operation of motor 49 is not continuous but Vis undercontrolof any desired automaticfmeans. so `that manual intervention is dispensed with. Yespecially in thefeeding of the coal, crushing the 60 fuel'beds and shaking of ashes from the grate.

The-air supply duct I8 extends through the front wall |-I and `forced air is supplied to the ductby va conventional blower or fan which may be suitably located exteriorly of the duct and .65 driven infanysuitablemanner as by vmeans of an electric motor. y The passage of air from the duct 'I8 to the gratos fis manually regulable. For instance, valvesor plates Hoover the 4outlet passages 23 of 70 such duct. Valvesy I3 are independently operaf bleaud each has horizontal pins 15fby means of which vitds-pivotedto duct 1 8, -and from one'of which pins-of eacl'iA valve, a crank or lever 14ex-1 ten-ds. A rod or. link. 1.6.is, pivoted at -'I'I to each lever 14 and such rods extend .through openings in the wall I-I to the exterior of the furnace for manual operation. Said rods 16 may be secured in open or closed positions or at diiferent adjustments in any suitable way as by passing pegs 15 through adjacent openings 19 in the rods and guide brackets 80.

The upper surfaces of the boxes I1 incline downwardly and inwardly to correspondingly dispose the fuel bed so that ashes will fall from the innermost section I into an ashpit 8| aided by guides 82 and 83 on the innermost section I6 and duct 18, respectively.

Duct 18 inclines similarly to the grates yand a closure 84 is pivoted at 85 to the duct 18` adjacent to ashpit 8l to facilitate cleaning of the duct. Closure 84 has a crank 85 to which one of the aforesaid operating rods 16 is pivoted. It will be noticed that of the total of six rods 16, they are arranged three on each side of the sections I5 and I6, A conventional door 81 is also provided at the front of duct 18.

Access to the interior ci. the structure may be had from the front through openings in the wall II, normally covered by conventional doors 88.

Presuming operation, coal ows by gravity from chute or hopper I2 through openings I3 into the path of movement of rams I4 while the latter are retracted, and onto hearth plates 61, and from the latter is pushed by the rams I4, progressively moving toward the rear of the Stoker onto the grates of boxes I1 forming the fuel bed. Through the reciprocation of pitmen 32, occurring periodically and automatically according to the control of motor 49, all of the sections I5 and I6 are moved as a unit toward the rear of the structure while all of the rams I4 slide in the opposite direction. This action advances the fuel bed as a whole, that is, it moves it away from the openings I3 and at the Same time moves the rams away from the fuel bed providing spaces or gaps into which the coal from the hopper flows. This action is timed so that when the sections I5 and I6 are rocked in the opposite direction and the rams I4 moved toward the fuel bed, such fuel bed will move to some extent unitarily with sections I5 and I6, thereby compressing and crushing the fuel bed, after which the sections I5 and I6 will move relatively to and will slip under the fuel bed toward the rams I4. At the same time, be-

cause of the rocking of the Sections I5 and I6, f

they will have up and down motions at their front and rear upper transverse edges, so that said edges, through rocking of the sections in opposite directions, will alternatively raise and recede as suggested by the full lines in the diagrams l of Figures 6 and 7, the steps between raised and receded positions being, for instance, two inches in practice. As a result, the fuel bed will be further agitated and crushed or broken up so as to facilitate maximum combustion and coaction with air. The motion imparted to the pitmen 34, and, accordingly, to the yconnected parts, may be continuous or intermittent, as preferred.

While the steps provided at the fuel bed surface or tops of the grate sections when the latter are shaken, moves the fuel forward, the inclination of such surface and the resistance offered by the forward fuel charge to the returning or receding motion of the grate sections also aids to produce the general forward moving action of the fuel bed.

The action may be further explained by assuming that there is a five inch stroke with ve retorts or boxes I1 where there will be four joints moving up and down at about two inches. With a ilve inch forward stroke and no-resistance, the fuel should move or carry the same, whereas with a five inch return with resistance, the fuel carry is about four and one-half inches or a one-half inch slippage to create the forward fuel action. It is to be noted that with one-half inch slippage with each stroke, every half-inch of the fuel bed is broken up four times at the fourjoints. This maintains equal density or porosity.

I claim aS my invention:

1. In a stoker structure, Stoker sections having grates, means mounting the sections for rocking on axes below the grates, beams for mounting in a furnace wall, relatively loose sealing bars slidably engaging the under surfaces of said beams, and journal connections between the sections and bars above the said axes.

2. In a Stoker structure, stoker sections having grates, means mounting the sections for rocking, beams for mounting in a furnace wall, relatively loose sealing bars slidably engaging the under surfaces of said beams and having bearings, and studs on the sections above their axes of movement journaled in said bearings.

3. In a Stoker structure, a plurality of stoker sections, said sections having compartments to receive air and provided with grates at the top to receive coal to provide a fuel bed, said grates being relatively long and arranged side by side with their longitudinal axes parallel, a ram, operating means for the ram including linkage connecting the compartments, means operable to move said ram away from the fuel bed and to rock all sections simultaneously in the direction opposite to the direction of movement of the ram, means for the supply of fuel between the ram and fuel bed the said moving means being operable thereafter to move the ram and sections toward each other for the purpose specified, an air supply duct beneath the compartments` and connections communicating with the duct and said compartments consisting of relatively movable parts.

4. In a stoker, a plurality of stoker sections, relatively loose sealing bars at opposite sides thereof. means of bearing engagement between the sections and bars, said sections having compartments to receive air and provided with grates at the top to receive fuel to provide a fuel bed, said grates Abeing relatively long and arranged side by side with their longitudinal axes parallel, linkage connecting the compartments in articulate relation, a ram movable above said compartments, means operable to rock all sections simultaneously in the same direction and move the ram in the opposite direction for reception of fuel between the ram and fuel bed and thereafter operable to move the ram and Stoker sections toward each other for the purpose specified, a supporting element, and connections between and communicating with the element and said compartments yieldable to compensate for rocking of the sections.

5. A Stoker Structure according to claim 4, wherein Said supporting element is an air supply duct.

6. A Stoker structure according to claim 4, wherein the second-mentioned means is operable to rock the sections on axes eccentric to normal.

'1. In a stoker structure, a plurality of stoker sections, said Stoker sections comprising compartments mounted for rocking movement, linkage connecting the compartments above the pivotal axes of the sections, a ram to move fuel onto the stoker sections to provide a fuel bed, means maar;

:operablettmovezsatdzram,zmeanssnorrelatedwlth aidmovingzmeans {operable to .frock all sections xin :the ,direction .npposite to the direction fof 'movement of the :ramLto--therebyzmove thez'ram .and :fuel :bed 'away from Seach V`other, fstructure `sprovding 'a zpassage .Ito :supply :fuel .between the n-'am :and Anel v.loed, :a support .bridging :the :ram .andfstoker sections '-.toJrr-:ceive saidfue1,1the said moving means:functioning:thereafteratormovethe ram and the sections .towardfeachzotherLfor .the .purposerspecifiedlandlmeansato supply 'air'.to said compartments, .the lastementioned means and -saidlcompartments having .fsurfaces inxrelatively yslidableengagement to permtthe aforesaidmock- "inggmovement `of the compartments.

18. Jn la Stoker structure, `Stoker :sections having grates fand compartments .for supply Yof :air :.beneathx thegrate-a ram'to :movexfuelfonto :the stokervsectionsto :provide ya' fuel Lbed, mechanism to ,move said ram, .means correlated 4with .said .mechanismoperable tozrock said section simulianeously .in -the direction opposite to .thedirec- .tionlof movement of the. ramA and1to therebyzmove the ram and fuel shed away from -each other, structure providngvajpassageto:supply fuel lbe :tween fthe ram :and .fuel bed. :,a :support :for' fuel .bridgingthe :ram and stoker Jsections -to receive :said fuel, .the:saidsmeehanismfunctioning lthere- `after -to move the :ram rand sections toward :each .other .for -the ,.purpose :specifed, an air fsupply duct, fand. meansstablishing ',oommunication'be- :tween fthe fcompartments and duct having 'com- ,ponents in relatively fslidable contact.

x9. Afstoker structure accordingto-.claiml having.connectionssupporting :thefgrates onzthefsaid .air .supply-.duct arranged in communication `with the latter -and iin articulate Vrelation .thereto -to compensate :for rocking-tof fthe sections.

.10. A .Stoker structure 3according `to Vclaim 8 having defiectors. .in ,the .compartments -in the ;path-of-.incoming.air.

111..'In3a Stoker structuraia :plurality df up kright stoker zsections :having normally :coplanar fuel-:supporting portions i'constructed :and farranged to l 'collectively 4receive f'coal -to provide la ffuel bed, .means iat .the Vcases fof said :sections mounting them for pivotal rocking 'movement teach :to a and from v@opposite sides :of the vertical planetin :which 'the axis 'of its 'pivot .is disposed, means 'above saidba'ses includingllinkage .articu- -lately connecting `said sections, a ram movable in a Lpath'atfa: rightangle:tosaidplanes,saidsections having edges parallel.tofsaidplanespand .motor :mechanism :connected to 'the 'ram arr'd to fsaidilinka'geltomovezthe'ramin a direction away from said sectionstomockallL sections and vthereby move the/saidaedgesv alternatelyfabove and below `the plane of fsaid :fuel-supporting portions 5to f'collectively advance the fuel be'd.

REFERENCES :CITED 'The :following 'references are of .frecord :in the 4lel of this ,patenti UNITED :STATES PATENTS Number Name Date .474,931 Whelan ',May 17,1892 `554,556 White (Feb..11,..1896 608,712 Pillatt -Aug. ..9, ,1898 915,034 .Lucke Mar..9,.l909 `925,723 ..Reagan.- ..Iune 22,1909

1,099,682 Wright -June .9, 1914 4,107,121 Shultz fAug. V11,1914 1,168,367 VWundrack Jan. ,18, 1916 .1,395,006 Patterson Oct.25,.1921 .1,475,159 .Masser Nov. 20,1923 1,512,812 Aram Oct. 2l, 924 r1,564,229 .Foresman Dec. 8,f1925 :1,630,738 Foresmanetal May 3l, 19.27 .2,276,327 `Mayers Mai-...17,1942 Y2,361,736 Bennett Oct. .31, 1944 

